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Y Fujitani

Publications and source records attributed to Y Fujitani.

72 records · Page 4Linked to original sources

Quick-freeze, deep-etch visualization of the nuclear pore complex.

We have visualized the nuclear pore complex (NPCx) three-dimensionally by quick-freeze, deep etching and suggest that NPCx is composed of four rings and associated filaments. The rings were located at the cytoplasmic side, at the nucleoplasmic side, and at the pore waist as well. Some of the filaments emanated toward the cytoplasm, some sprawled over the cytoplasmic face of the nuclear membrane, and some intervened the rings. The emanating filaments were considered to be vimentin filaments judging from the replica and thin-sectioned image.

Freeze Etching↗

Circadian rhythm of electrical activity and motility of the stomach in cats and their relation to sleep--wakefulness stages.

Polysomnographic recordings were done over continuous 3 days together with those of electrical and mechanical activities of the stomach using chronically implanted electrodes and force-transducer in unanesthetized and unrestrained state of 4 adult cats. Circadian rhythm of the basic electric rhythm (BER) and mechanical activity in the stomach accustomed to feeding schedule of once a day was divided into the two; the fed state from the end of feeding to 8 to 11 hr later and the succeeding fasting state. However, differentiation of the fasting state into the contractile and noncontractile periods, which is known in dogs, was not evident in cats. The mean BER interval was longer and the standard deviation was smaller in the fed state than in the fasting state. Among stages of wakefulness (W), drowsiness (D), light slow wave sleep (LS), deep slow wave sleep (DS) and REM sleep, the mean BER intervals in every total time during the fed state were compared with one another. A definite unidirectional finding obtained in all 4 cats was only that the mean BER intervals in the stage D were longer significantly than those in the stage W.

Animals↗

Somatosensory evoked potentials elicited by mechanical and electrical stimulation of each single pain or tactile spot of the skin.

Single pain and tactile spots on the dorsum of the right hand in man were stimulated by electric pulses and mechanical taps using a needle to a pain spot and a horse tail bristle to a tactile one. Somatosensory evoked potentials (SEPs) and far field potentials (FFPs) were observed in three volunteers by averaging of 200 or 400 samples of responses recorded from scalp points corresponding to the left and right somatosensory areas (LSA and RSA). For SEP measurements, the difference between responses at LSA and RSA was obtained in order to specify the optimum response at LSA. The patterns of SEPs elicited by mechanical or electrical stimulation to a pain spot were similar to those to a tactile one. The typical SEP to mechanical stimulation consisted of N23, P31, N40, P49, N64, P87, N114 and P147, while that to electrical stimulation did of N24, P33, N42, P52, N66, P95, N122 and P156. Consequently, mean peak latencies of the later components in SEPs elicited by mechanical stimulation were earlier than those to electrical one. The SEP amplitudes for mechanical stimulation were 1-3 microV and were larger than those to electrical one. By mechanical stimulation FFPs could not be obtained, while by electrical stimulation FFPs in peak latency of approximately 14 msec (P14) were seen. No specific components to sensory modality of pain or tactile sensation were observed either in SEPs or in FFPs.

Adult↗

Further studies of effects of chlorpromazine on the contingent negative variation.

The effect of 25 mg of chlorpromazine (CPZ) on the contingent negative variation (CNV) at Cz and Oz was studied in nine male subjects. Two kinds of warning stimulus (S1)--imperative stimulus--and motor response (MR) were used. A click as S1 was common to both, while either flashes or electrical stimulation was used as S2. Simultaneously with CNV recording, the reaction time of the finger movement as MR to S2 was measured in five of nine subjects. The results obtained were as follows. 1) CNV amplitudes after CPZ administration were decreased significantly both at Cz and Oz when S2 was flashes and only at Cz when S2 was electrical stimulation. 2) Significant positive correlations of CNV amplitudes between Cz and Oz were found both before and after the drug administration. 3) Reaction times to flashes and electrical stimulation as S2 were not affected by CPZ administration. 4) The reaction time to flashes was significantly shorter than that to electrical stimulation irrespective of pre- and post-administration of CPZ.

Adult↗